Solar Rover
The 4M Solar Rover is a green science kit in which children build a small vehicle that drives on sunlight alone. They assemble the chassis, fit the motor so its worm gear meshes with the rear axle gear, add four wheels, and mount an adjustable solar panel with reflectors on a support arm. A clean, empty soda can becomes the rover's body, encouraging recycling, and a transparent plastic shell is also included as an alternative body. In sunshine, the panel's solar cells generate current that turns the motor, while the gears slow the wheels so the motor can drive them more easily. Indoors, a 60-watt incandescent desk lamp can stand in for the sun under adult supervision, which is handy for school science fairs. A small crosshead screwdriver and an empty soda can are needed from home. No batteries are required.





